DRILLING TEMPLATES

GABARITS DE PERCAGE

English Abstract

A drilling template for use in jointing workpieces, the template consisting of
a substantially rectilinear bar with through holes through which holes can be
drilled in the workpieces to effect said jointing, a locating device for
locating the template relative to the workpieces when the though holes are
being drilled, and spacers for spacing the locating device from the bar to
enable the position of the through holes to be adjusted relative to the
workpiece.

French Abstract

La présente invention concerne des gabarits de perçage qui s~utilisent pour monter des pièces. Le gabarit se compose principalement d~une barre sensiblement linéaire dotée de trous traversants à travers lesquels on peut percer des trous dans les pièces pour effectuer ledit montage, d~un dispositif d~emplacement permettant de placer le gabarit par rapport aux pièces lorsque les trous traversants sont percés, et d~entretoises permettant d~espacer le dispositif d~emplacement de la barre en vue d~ajuster la position des trous traversants par rapport à la pièce.

Claims

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Claims:
1. A drilling template for use in jointing workpieces, with each of said
workpieces including an
end portion, a face, and a side, the template comprising:
a. a substantially rectilinear bar with through holes through which holes can
be drilled in
said workpieces to effect said jointing;
b. a first bolt passing through said bar in a direction which is perpendicular
to said
through holes;
c. a first plurality of stacked tabs, wherein
i. each of said first plurality of stacked tabs is pivotally attached to said
first bolt;
ii. each of said first plurality of stacked tabs has a particular thickness;
iii. each of said first plurality of stacked tabs pivots in a plane which is
perpendicular to said first bolt; and
iv. each of said first plurality of stacked tabs is independently pivotable
between a
first position in which said stacked tab is parallel to said rectilinear bar
and a
second position in which said stacked tab is perpendicular to said rectilinear
bar;
d. a second bolt passing through said bar in a direction which is
perpendicular to said
through holes;
e. a second plurality of stacked tabs, wherein
i. each of said second plurality of stacked tabs is pivotally attached to said
second
bolt;
ii. each of said second plurality of stacked tabs has a particular thickness;
and
iii. each of said second plurality of stacked tabs pivots in a plane which is
perpendicular to said second bolt; and

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iv. each of said second plurality of stacked tabs is independently pivotable
between a first position in which said stacked tab is parallel to said
rectilinear bar
and a second position in which said stacked tab is perpendicular to said
rectilinear
bar; and
f. whereby said user can offset said through holes relative to said face of
said workpiece
by a varying amount by rotating a selected stacked tab in said first plurality
of stacked
tabs and a selected stacked tab in said second plurality of stacked tabs into
said second
position and placing said stacked tabs in said second position flat against
said face of said
workpiece while said rectilinear bar is mated to said end of said workpiece.
2. A template according to claim 1, wherein:
a. said first bolt includes a first nut threadedly engaged thereto so that
when said first nut
is tightened said first nut locks said first plurality of stacked tabs in
position; and
b. said second bolt includes a second nut threadedly engaged thereto so that
when said
second nut is tightened said second nut locks said second plurality of stacked
tabs in position.
3. A template according to claim 1 further comprising:
a. a third bolt connected to said rectilinear bar, with said third bolt being
perpendicular to
said through holes, said first bolt, and said second bolt; and
b. a third bolt tab pivotally connected to said third bolt, wherein said third
bolt tab is
pivotable between a first position in which said third bolt tab is parallel to
said through holes and
a second position in which said third bolt tab is perpendicular to said
through holes.
4. A template according to claim 1, wherein said spacers all have the same
thickness to provide a
uniform displacement of the bar relative to said face of said workpiece.
5. A drilling template according to claim 1, wherein said spacers have varying
thicknesses to
provide a varying displacement of the bar relative to said face of said
workpiece.

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6. A drilling template according to claim 1, further comprising a second
substantially rectilinear
bar, said second rectilinear bar being connected to said first rectilinear bar
by said first and
second bolts so that said second rectilinear bar is parallel to said first
rectilinear bar, said second
rectilinear bar including through holes which are parallel to said through
holes in said first
rectilinear bar.
7. A drilling template according to claim 6, wherein:
a. said first bolt includes a first nut threadedly engaged thereto so that
when said first nut
is tightened said first nut locks said first plurality of stacked tabs in
position; and
b. said second bolt includes a second nut threadedly engaged thereto so that
when said
second nut is tightened said second nut locks said second plurality of stacked
tabs in position.
8. A drilling template according to claim 6, further comprising:
a. a third bolt connected to said first rectilinear bar, with said third bolt
being
perpendicular to said through holes, said first bolt, and said second bolt;
and
b. a third bolt tab pivotally connected to said third bolt, wherein said third
bolt tab is
pivotable between a first position in which said third bolt tab is parallel to
said through holes and
a second position in which said third bolt tab is perpendicular to said
through holes.

Description

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Drilling Templates
This invention concerns drilling templates or jigs, particularly
for drilling holes in the ends and edges of wood and wood based
workpieces.
The drilling of holes in the ends and edges of wood and wood
based workpieces is widely used in the construction of furniture
from wood and wood based sheets. Typically such joints are
formed by drilling holes into an end of one sheet and also into
a surface of another sheet, dowels being inserted into the
respective holes to locate one sheet relative to the other. As
is well known, the accuracy of the resulting joints depends on
the accuracy with which the respective holes are drilled into
the respective sheets. More particularly, the holes in the ends
of the sheets need to be accurately positioned relative to one
surface of sheet, and the holes in the surfaces of the sheets
need to be accurately positioned relative to the ends of the
sheets.
Drilling templates for producing such joints have been proposed
hitherto.

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An example of one such template consists of a L-section block
which is clamped to a workpiece, holes in the workpiece being
drilled through holes in the block. These templates suffer from
a number of disadvantages, notably the inability to change the
position of the resultant holes relative to the thickness of a
workpiece and the difficulty in accurately positioning the
templates, relative to the workpieces. A range of different
sizes of template could be used to overcome the former of these
disadvantages. However, the manufacturers of such templates
tend to produce ranges of templates for substantially different
thicknesses of workpiece which also have different diameter
through holes. Furthermore, the restricted number of'through
holes through such templates make it difficult to position the
templates accurately relative to edges of the workpieces, and
hence make accurate registration of dowel holes to be achieved
between workpieces which are to be jointed.
According to the present invention there is provided a drilling
template for use in jointing workpieces, the template comprising
a substantially rectilinear bar with through holes through which
holes can be drilled in the workpieces to effect said jointing,
locator means for locating the template relative to the
workpieces when said though holes are being drilled, and spacer
means for spacing the locator means from the bar to enable the
position of the through holes to be adjusted relative to a
surface of the workpiece being drilled.
Embodiments of drilling template in accordance with the present
invention will now be described with reference to the
accompanying drawings in which:-
Fig. 1 is a side view of a first embodiment;
Fig. la is a plan view of a part of the embodiment of Fig. 1;
Fig. lb is a plan view of a part of the embodiment shown in Fig.
2-5;

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Fig. 2 is a perspective view of the first embodiment positioned
on the end of a workpiece;
Fig. 3 corresponds to Fig. 2 but with the template positioned on
the end of a thicker workpiece;
Fig. 4 corresponds to Fig. 2 but with the template positioned on
the end of a workpiece of circular section; and
Fig. 5 is a perspective view of a second embodiment.
The template shown in Figs. 1 to 4 consists of a square section
rectilinear bar 1 having a plurality of parallel through holes 2
perpendicular to one surface of the bar 1, alternate holes 2'
being countersunk, and a plurality of further through holes 3
passing through the bar 1 perpendicular to surfaces of the bar 1
through which the holes 2 pass.
Bolts 4 (only one being shown in Fig. 1) are located in the
holes 3, their heads 5 preventing them from passing through the
bar 1. On each of the bolts 4, on the opposite side of the bar
1 from the heads 5, is a plurality of tabs 6 which are pivotal
on the bolts 4. Knurled nuts 7 are threaded on to the bolts 4,
and spring washers 8 between the nuts 7 and the tabs 6, serve to
lock the tabs 6 in position when the nuts 7 are tightened on to
the tabs 6.
The bar 1 has threaded holes 10 in each end, a bolt 11 being
located in one of the holes 10. A further tab 12 is located on
the bolt 11, and a knurled nut 13 and a spring washer 14 can be
used to lock the tab 12 on the end of the bar 1. The tab 12 has
a slotted hole 15 therein which enables the tab 12 to be slid
relative to the bolt 11 in addition to being rotated about the
bolt 11.
The holes 2 in the bar 1 are positioned along the center line of
the bar 1 and at regular, predetermined distances from each

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other and from each end of the bar 1. This enables holes to be
drilled through the holes 2 at predetermined intervals and at a
predetermined distance from the ends of the bar 1.
As shown in Fig. 2, the tabs 6 are all locked in position by the
respective bolts 4 and washers 8 so that they extend
substantially perpendicularly to the length of the bar 1. The
tab 12 is locked in position on the bar 1 using the nut 13, the
tab 12 having previously been slid so that it extends as far as
possible from the bar 1 and is positioned so that it extends in
substantially the same direction as the tabs 6 but perpendicular
thereto.
The bar 1 is then located on an end portion of a workpiece 16
with the tabs 6 flat on one face of the workpiece 16 and the tab
12 contacting a side of the workpiece, for example using a
G-cramp (not shown) or using screws screwed into the workpiece
16 through countersunk holes 2' in the bar 1.
As shown in Fig. 2, the workpiece 16 is of substantially the
same thickness as the bar 1, and so drilling holes in the end of
the workpiece 16 through the holes 2 using a drill bit of
substantially the diameter of the holes 2 will result in the
drilled holes being substantially along the center line of the
thickness of the workpiece 16, and at a predetermined distance
from one edge of the workpiece 16 governed by the dimensions of
the bar 1 and the positions of the holes 2.
The bar 1 can then be used to drill holes in the surface of a
further workpiece which is to be jointed to the workpiece 16 by
positioning the bar 1 on the surface of an end portion of the
further workpiece with the tabs 6 abutting the end of the
further workpiece and the tab 12 abutting a side of the further
workpiece. Holes drilled through the holes 2 in the further
workpiece will then be positioned so that when suitably sized
dowels are inserted into them, the two workpieces will form an
accurately aligned joint.

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Fig. 3, which corresponds to Fig. 2, shows the bar 1 being used
to joint thicker workpieces. In order to effect this, the tabs
6 on the bar 1 have been loosened by undoing the nut 4, and then
rotating them so that they extend along the length of the bar 1
rather than perpendicular thereto, and the tabs 6 are then
locked in their new positioned by the nut 4.
The number of tabs 6 which are rotated will depend on the
thickness of the thicker workpiece, the tabs 6 being of
particular thicknesses to displace the bar 1 across the end of
the thicker workpieces by particular distances to bring the
centers of the holes 2 on to the center line of the end of the
thicker workpieces. For example, if the bar 1 has a cross
section of 16mm x 16mm, all of the tabs 6 will be positioned
perpendicular to the bar 1 if holes are to be drilled along the
center line of a workpiece 16mm thick. However, if holes are to
be drilled along the center line of a 18mm thick workpiece, a
single 1mm thick tab abutting the bar 1 will be rotated to be in
line with the bar 1, the center line then being (8 + 1)mm, that
is 14x19mm from the surface of the workpiece.
The tabs 6 can all be of the same thickness or of a variety of
thicknesses according to the desired displacements of the center
line of the holes 2 in the bar 1, and they can, if desired, be
used in combination to provide a variety of displacements. For
example they can be 1, 2, 3 or more mm thick. As will be
appreciated, at least one tab 6 will be required to position the
bar 1 relative to the workpiece with which it is being used.
The bar 1 can be of rectangular cross section rather than square
as shown in the drawings.
Referring to Fig. 4, the template can be seen being used to
drill radial holes in around workpiece 17.
The embodiment shown in Fig. 5 is a modification of the
embodiment shown in Figs 1-4, a second square section bar 20
being attached to the bar 1 by the bolts 4 which pass through

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holes in both of the bars 1 and 20. The bar 20 also has a
plurality of through holes 22 with alternate countersunk through
holes 22', the latter being useful for attaching the bar 20 to
the workpiece. Once attached to a workpiece, the bar 20 can be
used as a datum for repositioning the bar 1 relative to the
workpiece. This is facilitated by the bar 20 being longer than
the bar 1, part of the bar 20 having been cut off in Fig. 5.
The embodiment shown in Fig. 5 can also be used to drill double
rows of holes in workpieces, and the number of tabs 6 swivelled
into line with the bar 1 can be adjusted to position the holes 2
and 22 where required relative to the workpiece. Further bars 1
and/or 21 can also be attached in order to produce further rows
of holes in the workpiece.

Representative Drawing